A novel anti-photoaging ingredient with the effect of iron sequestering

Background: The reactive oxygen species generated by ultraviolet rays causes various types of cutaneous damage, such as lipid peroxidation and denaturation of the extra-cellular matrix. The accumulation of such damage contributes to skin aging, especially the formation of wrinkles. It has been suggested that iron ions, released from iron-binding proteins by ultraviolet rays, promote the production of radicals and accelerate the formation of wrinkles. Thus, sequestering iron ions might be effective in suppressing wrinkle formation. Objective: Our purpose is to develop new cosmetic materials with iron sequesteing capacity to suppress skin photoaging, especially wrinkle formation. Method: We designed a novel compound, N-(4-pyridoxytmethylene)-L-serine (PYSer), as a cosmetic material with a structure similar to a biological iron sequestering protein. We studied its effect on suppressing hydroxyl radical generation and wrinkle formation in a mouse model for skin photoaging. Results: PYSer almost completely inhibited the generation of hydroxyl. radicals by iron ions. In contrast, EDTA, a typical metal chelator, did not suppress hydroxyl radical production, but enhanced it. Furthermore, PYSer delayed UVB-induced wrinkle formation and skin thickening. Conclusion: This study demonstrates that PYSer suppresses photoaging, particularly, wrinkle formation and skin thickening. (c) 2005 Japanese Society for Investigative Dermatology. Elsevier Ireland Ltd. All rights reserved.